When ozone generators are used for medical purposes, it is necessary to control the ozone concentration precisely.
It is common that ozone generators heretofore known, based on the corona discharge principle, use variacs to regulate the amplitude of the alternating current high voltage across the electrodes of the ozone generator. Variacs have the disadvantage that they need to be adjusted by mechanical means.
One method to control the amount of ozone produced by ozone generators, based on the corona discharge principle, use triacs and silicon controlled rectifiers to regulate the amount of ozone used in the ozone generator. It is however not possible to vary the phase angle to the gate of such triacs in small increments in an accurate manner.
Another method to control the amount of ozone produced by ozone generators, based on the corona discharge principle, is to vary the frequency of the voltage pulses applied to the electrodes. This method gives a more reproducible control with better resolution than the amplitude and phase control circuits. The disadvantage is that the control is only effective over a limited frequency range because of the inherent characteristics of the high voltage transformer.
It is common in ozone generator control systems heretofore known that the control means are electrically connected to the ozone generation means through electrical conductors. The noise from the high voltage ozone generation means therefore interferes with the reliable operation of the control means.
Many ozone generator control systems using the above described control methods therefore suffer from a number of disadvantages:
(a) In the ozone generator control systems that use variacs to regulate the amplitude of the alternating current high voltage across the electrodes of the ozone generator, it is necessary to use mechanical means for the adjustment. This is a disadvantage when electronic controls are use. PA1 (b) When triacs and silicon controlled rectifiers are used to regulate the amount of ozone used in the ozone generator, it is not possible to vary the phase angle to the gate of such triacs in small increments in an accurate manner. PA1 (c) In the ozone generator control systems where the frequency of the voltage pulses applied to the electrodes is varied, the control is only effective over a limited frequency range because of the inherent characteristics of the high voltage transformer. PA1 (d) The noise from the high voltage ozone generation means interferes with the reliable operation of the control means in ozone generator control systems where the control means are electrically connected to the ozone generation means through electrical conductors. PA1 (a) to provide an ozone generator control system which uses electronic means for the control of the production of ozone in an ozone generator. PA1 (b) to provide an ozone generator control system which can adjust the amount of ozone produced accurately in small increments. PA1 (c) to provide an ozone generator control system which can adjust the amount of ozone produced accurately over the full range of ozone production. PA1 (d) to provide an ozone generator control system which is electrically isolated from the noise interference from the high voltage ozone generation means.